African sharptooth catfish

Water parameters

Minimum tank: 500 L per individual at harvest size.

Feed and growth

Feed protein

35% target

Daily feed (warm)

2.00% of body weight

Daily feed (cool)

0.70% of body weight

Max density

80 g per litre

A 60000 g adult eats about 1200.0 g of feed per day at optimum. 10 fish at adult size: ~12000 g daily.

Legality

Rules vary by jurisdiction and change over time. Verify with your local fisheries or wildlife authority before stocking.

Unlisted jurisdictions default to "check local regulations".

Origin and habitat

Native to almost the entire African continent, absent from Maghreb, Upper and most of Lower Guinea, and the Cape province; also native to parts of the Middle East including Jordan, Israel, Lebanon, Syria, and southern Turkey. The most widely distributed fish in Africa. The genus name Clarias comes from Greek chlaros ("lively"), referencing the ability to live a long time out of water; gariepinus is named after the Gariep River (Hottentot name for the Orange River) in South Africa. A member of the family Clariidae (airbreathing catfishes). Prefers floodplains, sluggish rivers, lakes, and dams; can withstand low dissolved oxygen and highly turbid waters. Has a suprabranchial organ that allows atmospheric air breathing, enabling survival in near-anoxic conditions and short overland movement between water bodies. Introduced worldwide in the early 1980s for aquaculture; now found in Brazil, Vietnam, Indonesia, India, and many other countries, with several reporting adverse ecological impact. Can grow to a maximum reported length of 170 cm and weight of 60 kg; culture size is typically 0.5–2 kg at harvest. The genus was revised in the 1980s by Teugels, synonymizing several widespread species (C. capensis, C. mossambicus, C. lazera) under C. gariepinus. One of the most widely farmed species in Africa and a leading candidate for aquaculture development in sub-Saharan regions; also cultured in South America, Asia, and China using both extensive and intensive methods. Spawning takes place during the rainy season in flooded deltas. Can generate electric organ discharges during aggressive interactions.

Climate and outdoor ponds

Climate

tropical (needs warm water year-round)

USDA zones

9–13 (winter low around -7°C or warmer)

Heating needed

yes

Cooling needed

no

Care notes

One of the hardiest aquaculture species available. The suprabranchial organ allows air breathing, so they tolerate very low dissolved oxygen and can survive out of water for extended periods if the skin stays moist. Temperature tolerance is wide: 8-35°C, with optimum growth at 25-33°C and peak performance at 30°C. Recorded pH tolerance is 6.5-8.0; fry suffer 100% mortality at pH 2, 3, 10, 11, and 12, with median lethal pH at 4.3 (acid) and 9.2 (alkaline). Growth is fast: roughly 450-500g in 180-210 days on 32-35% protein feed. FCR varies widely with conditions: 1.5-2.5 is typical under good management, with some RAS operations reporting below 1.5. Optimal dietary protein is 35% for fingerlings and juveniles; 32% is adequate for grow-out. Stocking density can be high in recirculating systems because of the air-breathing ability. Feed: sinking pellet. They are opportunistic omnivores and will eat dead fish, simplifying mortality management. The main regulatory issue is invasiveness: C. gariepinus is prohibited in many US states, all of Australia, and parts of Europe because escaped fish establish feral populations. The air-breathing ability means they can migrate overland during rain, making containment difficult. Check local regulations before acquiring.

Further reading

• Aquaponics water chemistry: balancing pH for fish and plants
• Fish for aquaponics: tilapia vs everything else